This invention relates to method and apparatus for the detection of the presence of ice on a surface.
The formation of ice on surfaces such as roads and the wings of aircraft may present safety hazards. In the case of aircraft, the hazard may present itself quite rapidly as the buildup of ice, once its formation is initiated, can proceed at a fast pace, sometimes with serious consequences. As has been tragically learned, deicing of an aircraft waiting to take off can produce a false sense of security, because after only a few minutes, ice formation can begin again and proceed at a rapid pace.
Efforts up to now to provide a warning at the presence of ice have produced a variety of techniques and systems which will indicate that ice is present. However, such arrangements have generally proven to be unacceptable for regular use due to a variety of factors, including the need for excessively complex apparatus. Problems of cost, lack of reliability, false warnings, and slow response times are some of the reasons why no system presently available has become generally accepted for use.
A number of ice detection systems are disclosed in U.S. Pat. Nos. 4,688,185, 4,570,881, 3,517,900, 3,276,254, 2,432,669, 2,359,787, 2,127,823, and 4,766,369. None of the preceding patents teaches the present invention.